KC Gardens

Bagworm followup question


I have a related question and one comment.

Was this an especially bad year for bagworms? Have they ever stopped emerging and feeding? I don’t ever remember being so diligent about spraying my conifers with Bt four or five times over the course of a month and still having thousands of bags on everything. Are the bagworms relentless this year or what?!

We have damage to junipers, arborvitaes, a gloe blue spruce and our Black Hills spruces. They’re even haging off the dappled willows and crape myrtles, but those will be hard-pruned next spring, so there’s no point pulling them off.

And my comment: Junipers don’t re-leaf too well, but arborvitaes should grow through the damage. One of ours is already recovering. Yews will grow back readily, no problem. - Tina -


  1. 7 months, 3 weeks ago

    Referring to the Kansas Insect Newsletter from June 7 of this year, the entomologist suggested that the emergence this year might be delayed due to cooler, moister weather.

    Also under discussion were the various control measures. Bt subsp Kurstaki, used for bagworms is most active on the young, and must be ingested. Additionally, Bt is very sensitive to UV rays, such that it must be applied frequently and covering the plant thoroughly. Bt would readily wash off due to rain, thus needing to be reapplied.

    Sorry I don’t know why you had so many bagworms. All I can do is join you in saying, “Yuk!”

    Carole Johnson County Extension Master Gardener

  2. 7 months, 3 weeks ago

    I sprayed in the wee hours of themornings, beginning when I first saw them back in June. I inspected some areas of the garden more than others, but all my junip[ers and arborvitaes and spruces (even the globe blue spruce) were hit badly, and over an extended period. Some bags stayed very small because I got them in time. Many more grew huge.

    Now here is a funny one. I used my compost fork just last weekend, and then I put it in my garden cart. Today I grabbed that fork and all four tines had bagworm bags! All neatly and strongly secured with that white silk they spin. There were bags on my pump sprayer head as well, and I only used that a few days ago! Plants i inspect daily because they are next to our patio still have them, even a day after I have combed through them.

    All I can do is drench all the evergreens early and often next year, because I can’t possibly pick them all.

Sign in with Facebook to comment.

Copyright 2014 The Kansas City Star.  All  rights  reserved.  This material may not be published, broadcast, rewritten  or redistributed.